Drew Peterson's stepbrother said he believed the former cop was planning to murder someone in October 2007, but for the first time he described publicly his sickening realization that the person Peterson wanted to kill was his wife, Stacy.
Thomas Morphey recounts the moment he concluded that Peterson's target was his 23-year-old wife.
"All I could think ... was he was killing her while I was standing there," Morphey told "Good Morning America."
Morphey went to the police, won immunity for...Full Story